This normal activity leads to less sperm in young men

Using time spent watching television, the researchers found that otherwise healthy men were clocking in lower sperm counts than their active peers. In fact, men who watched more than 20 hours of TV a week had 44 percent less sperm count than men who watch almost no television.

“We know very little about how lifestyle may impact semen quality and male fertility in general so identifying two potentially modifiable factors that appear to have such a big impact on sperm counts is truly exciting,” lead author Audrey Gaskins, a doctoral student at HSPH, said in a press release.

On the flip side, men who exercised in a moderate to vigorous fashion for 15 or more hours a week had 73 percent higher sperm count than those exercising less than five hours a week.

“Mild exercise did not affect sperm quality,” the study found.

The authors caution that, while a reduced sperm count has been linked to lower fertility, it does not necessarily preclude men from fathering a child.